function checkUser(str) {
    $.ajax({
        type: "GET",
        async: false,
        url: "http://115.29.136.190:8080/help/usr/user/getUserStatus.do",
        contentType: "application/json; charset=utf-8",
        dataType: 'json',
        xhrFields: {
            withCredentials: true
        },
        crossDomain: true,
        success: function(result) {
            alert(result.message);

        }
    });
}